proper options parsing

ruby/bin/gosuhunt

@@ -2,12 +2,13 @@
 # frozen_string_literal: true
 
 require 'gosu'
+require 'optparse'
 
 require 'minehunt'
 
 class GosuHunt < Gosu::Window
-  def initialize( number_of_mines = 20 )
-    @scale = 3
+  def initialize( number_of_mines, scale )
+    @scale = scale
     @sprite_size = 6
 
     @number_of_mines = number_of_mines
@@ -114,7 +115,20 @@ class GosuHunt < Gosu::Window
   end
 end
 
-number_of_mines = 20
-number_of_mines = ARGV.first.to_i if ARGV.length == 1
+options = { number_of_mines: 20,
+            scale: 3 }
+OptionParser.new do |opts|
+  opts.banner = 'Usage: gosuhunt <options>'
 
-GosuHunt.new( number_of_mines ).show
+  opts.on( '-m', '--mines INT' ) do |nb_mines|
+    options[:number_of_mines] = nb_mines.to_i
+  end
+
+  opts.on( '-s', '--scale INT' ) do |scale|
+    options[:scale] = scale.to_i
+  end
+end
+            .parse!
+
+GosuHunt.new( options[:number_of_mines], options[:scale] )
+        .show

ruby/bin/minehunt

@@ -2,6 +2,7 @@
 # frozen_string_literal: true
 
 require 'curses'
+require 'optparse'
 
 require 'minehunt'
 
@@ -108,7 +109,14 @@ def ncurses_main( number_of_mines )
   exit!
 end
 
-number_of_mines = 20
-number_of_mines = ARGV.first.to_i if ARGV.length == 1
+options = { number_of_mines: 20 }
+OptionParser.new do |opts|
+  opts.banner = 'Usage: minehunt <options>'
 
-ncurses_main( number_of_mines )
+  opts.on( '-m', '--mines INT' ) do |nb_mines|
+    options[:number_of_mines] = nb_mines.to_i
+  end
+end
+            .parse!
+
+ncurses_main( options[:number_of_mines] )